Nothing significant. I am almost at the $18 mark and that is after having my Google Adsense acount for almost 8 months. That being said, I am just over $2 a month. Broken down like that, it looks darn pathetic.
Yet, on a positive note, my earnings have been increasing more and more each month and with each new hub. The money you make also depends on what topics your write about as well. In time, it will happen. Whether it will help you retire, I haven't figured that out, but persistance is the key. Keep at it and it will pay off.